Active probe card for electrical wafer sort of integrated circuits

Abstract

A testing apparatus includes a tester and a probe card system that includes a probe card connected to the tester, and an active interposer connected to the probe card and wirelessly coupled with a device to be tested. The active interposer includes pads positioned on its free surface facing the device. The pads are positioned with respect to pads of the device so that each pad of the active interposer faces a pad of the device and is separated therefrom by a dielectric. Each pair of facing pads forms an elementary wireless coupling element which allows a wireless transmission between the active interposer and the device. The active interposer also includes an amplifier circuit configured to amplify wireless signals from the device before forwarding them to the tester. The probe card system includes a transmission element able to transmit a power voltage from the tester to the device.

The invention claimed is: 
     
       1. A probe card system for a testing apparatus, comprising:
 a probe card configured to be coupled to a tester of the testing apparatus, 
 an active interposer coupled to the probe card and configured to be wirelessly coupled with a device to be tested that includes a plurality of pads, said active interposer including:
 a free surface configured to face the device; 
 a plurality of pads positioned on the free surface and configured to respectively face the pads of the device and to be separated from the pads of the device by a dielectric, each pad of the active interposer being configured to form, with the respective pad of the device, an elementary wireless coupling element that allows a wireless transmission between the active interposer and the device; and 
 an amplifier circuit configured to amplify wireless signals from the device and forward the amplified wireless signals to the tester; and 
 
 a transmission element coupled to the active interposer and configured to transmit a supply voltage to the device. 
 
     
     
       2. A probe card system according to  claim 1 , wherein:
 said probe card includes a body, a surface configured to face the tester, a plurality of contact pads positioned on the surface of the probe card, and a plurality of conductive through connections extending through the body of the probe card; and 
 said active interposer further comprises a plurality of conductive paths respectively coupling the pads of the active interposer, by via the through connections, to the contact pads of the probe card. 
 
     
     
       3. A probe card system according to  claim 1 , wherein the active interposer includes a body with a hole extending completely through the body of the active interposer, and said transmission element comprises a probe protruding from the probe card and crossing the body of the active interposer through the hole, said probe being configured to contact a corresponding pad of the device transmit the supply voltage to said device. 
     
     
       4. A probe card system according to  claim 1 , wherein said transmission element comprises a power/ground pad realized on said active interposer and having a bigger size than the pads of the plurality of pads of the active interposer and configured to provide, in a wireless manner, the supply voltage to a corresponding pad of the device. 
     
     
       5. A probe card system according to  claim 1 , wherein the active interposer comprises a semiconductor substrate, or a flexible substrate, or a glass substrate, or a substrate suitable for printed circuit manufacturing techniques. 
     
     
       6. A probe card system according to  claim 1 , comprising a probe head coupled to the probe card and including a recess, wherein the active interposer includes a body positioned in the recess of the probe head and a passive substrate in contact with the body of the active interposer and having at least a portion configured to face the device. 
     
     
       7. A probe card system according to  claim 6 , wherein:
 the free surface of the active interposer is a free surface of the passive substrate; 
 the pads of the active interposer are positioned on the free surface of the passive substrate; 
 the body of the active interposer houses the amplifier circuit; 
 the active interposer includes a plurality of conductive bumps coupled to the amplifier circuit and positioned on the body of the active interposer; and 
 said passive substrate comprises conductive paths coupling the pads of the active interposer to the conductive bumps. 
 
     
     
       8. A probe card system according to  claim 6 , wherein said passive substrate is a flexible layer having first and second wings coupled between the probe card and the probe head and a portion configured to face the device. 
     
     
       9. A probe card system according to  claim 6 , wherein said probe head includes a body and a hole extending completely through the body, and said transmission element comprises a probe positioned in the hole in the body of the probe head, protruding from the probe head, configured to extend towards a corresponding pad of the device, and configured to transmit the supply voltage to said device. 
     
     
       10. A probe card system according to  claim 6 , wherein said transmission element comprises at least one power/ground pad realized on said passive substrate and having a bigger size than the pads of the plurality of pads of the active interposer and configured to provide, in a wireless manner, the supply voltage to a corresponding pad of said device. 
     
     
       11. A probe card system according to  claim 1 , comprising a wafer probe that includes a plurality of active interposers, each configured to face a respective device to be tested of a wafer. 
     
     
       12. A probe card system according to  claim 1 , further comprising on-board test circuitry positioned in the active interposer and configured to perform some testing steps on the device and forward results of such testing steps to the testing apparatus. 
     
     
       13. A probe card system according to  claim 1 , further comprising a wireless power transmission circuit positioned in the active interposer and configure to supply the supply voltage to the transmission element. 
     
     
       14. A testing apparatus, comprising:
 a tester; 
 a probe card electrically coupled to the tester; 
 an active interposer coupled to the probe card and configured to be wirelessly coupled with a device to be tested that includes a plurality of pads, said active interposer including:
 a free surface configured to face the device; 
 a plurality of pads positioned on the free surface and configured to respectively face the pads of the device and to be separated from the pads of the device by a dielectric, each pad of the active interposer being configured to form, with the respective pad of the device, an elementary wireless coupling element that allows a wireless transmission between the active interposer and the device; and 
 an amplifier circuit configured to amplify wireless signals from the device and forward the amplified wireless signals to the tester; and 
 
 a transmission element coupled to the active interposer and configured to transmit a supply voltage to the device. 
 
     
     
       15. A testing apparatus according to  claim 14 , wherein:
 said probe card includes a body, a surface configured to face the tester, a plurality of contact pads positioned on the surface of the probe card, and a plurality of conductive through connections extending through the body of the probe card; and 
 said active interposer further comprises a plurality of conductive paths respectively coupling the pads of the active interposer, by via the through connections, to the contact pads of the probe card. 
 
     
     
       16. A testing apparatus according to  claim 14 , wherein the active interposer includes a body with a hole extending completely through the body of the active interposer, and said transmission element comprises a probe protruding from the probe card and crossing the body of the active interposer through the hole, said probe being configured to contact a corresponding pad of the device transmit the supply voltage to said device. 
     
     
       17. A testing apparatus according to  claim 14 , wherein said transmission element comprises a power/ground pad realized on said active interposer and having a bigger size than the pads of the plurality of pads of the active interposer and configured to provide, in a wireless manner, the supply voltage to a corresponding pad of the device. 
     
     
       18. A testing apparatus according to  claim 14 , comprising a probe head coupled to the probe card and including a recess, wherein the active interposer includes a body positioned in the recess of the probe head and a passive substrate in contact with the body of the active interposer and having at least a portion configured to face the device. 
     
     
       19. A testing apparatus according to  claim 18 , wherein:
 the free surface of the active interposer is a free surface of the passive substrate; 
 the pads of the active interposer are positioned on the free surface of the passive substrate; 
 the body of the active interposer houses the amplifier circuit; 
 the active interposer includes a plurality of conductive bumps coupled to the amplifier circuit and positioned on the body of the active interposer; and 
 said passive substrate comprises conductive paths coupling the pads of the active interposer to the conductive bumps. 
 
     
     
       20. A testing apparatus according to  claim 18 , wherein said probe head includes a body and a hole extending completely through the body, and said transmission element comprises a probe positioned in the hole in the body of the probe head, protruding from the probe head, configured to extend towards a corresponding pad of the device, and configured to transmit the supply voltage to said device. 
     
     
       21. An active interposer for a testing apparatus for testing a device that includes a plurality of pads, the active interposer comprising:
 a body configured to be coupled to a probe card of the testing apparatus, the body including a free surface configured to face the device; 
 a plurality of pads positioned on the free surface and configured to respectively face the pads of the device and to be separated from the pads of the device by a dielectric, each pad of the active interposer being configured to form, with the respective pad of the device, an elementary wireless coupling element that allows a wireless transmission between the active interposer and the device; 
 an amplifier circuit configured to amplify wireless signals from the device and forward the amplified wireless signals to the tester; and 
 a transmission element configured to transmit a supply voltage to the device. 
 
     
     
       22. An active interposer according to  claim 21 , comprising a hole extending completely through the body, wherein said transmission element comprises a probe crossing the body through the hole, said probe being configured to be electrically coupled to the probe card and contact a corresponding pad of the device transmit the supply voltage to said device. 
     
     
       23. An active interposer according to  claim 21 , wherein said transmission element comprises a power/ground pad positioned on said body and having a bigger size than the pads of the plurality of pads of the active interposer and configured to provide, in a wireless manner, the supply voltage to a corresponding pad of the device. 
     
     
       24. An active interposer according to  claim 21 , comprising a passive substrate in contact with the body of the active interposer and having at least a portion configured to face the device. 
     
     
       25. An active interposer according to  claim 24 , wherein:
 the free surface of the active interposer is a free surface of the passive substrate; 
 the pads of the active interposer are positioned on the free surface of the passive substrate; 
 the body houses the amplifier circuit; 
 the active interposer includes a plurality of conductive bumps coupled to the amplifier circuit and positioned on the body; and 
 said passive substrate comprises conductive paths coupling the pads of the active interposer to the conductive bumps.